Résumé : Background: Relatively high morbidity rates are reported after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). However, early predictors of complications after CRS plus HIPEC have not been identified. The aim of this study was to evaluate the predictive role of early postoperative serum C-reactive protein (CRP) level (Day 2–4) for the detection of post-operative complications. Patients and methods: We performed a retrospective study including 94 patients treated with complete CRS (R1) and HIPEC for PC from various primary origins (2011–2016). Post-operative complications were recorded. The values for postoperative inflammatory markers (white blood cells [WBC] and platelet counts, CRP) were compared between the different groups. Results: CRP on post-operative days 2–4 was significantly higher in patients with than without complications (124 mg/L vs 46 mg/L; p < 0.0001) and higher in those with more major complications (162 mg/L vs 80 mg/L; p < 0.0012). WBC and platelet counts showed no difference within 5 days postoperatively. Conclusion: CRP levels, and kinetics mainly, between post-operative day 2 and 4, are decisive predictive markers of early and late post-operative complications after CRS plus HIPEC. The presence of post-operative complications should be suspected in patients with a high CRP mean, and a plateau level (days 2–4).